DE 103 42 471 A1 reveals a robot control system for a multiaxial painting robot, which moves a Tool Centre Point (TCP) along a predetermined robot path. This known robot control system may take account of and compensate mechanical elasticities of the individual robot axes, in order to improve the positioning accuracy of the painting robot. In this instance, the individual robot axes of the painting robot are actuated in each case by one axis controller, the mechanical elasticity of the painting robot being taken into account in that the deviation of the axis controller of a relatively flexible robot axis acts, in the context of axially overlapping coupling, on an axis controller of a relatively rigid axis.
This known robot control system has already proven advantageous, but it is desirable, in particular in the case of highly dynamic robot movements, to take even better account of mechanical elasticities of the painting robot and to provide even better compensation, in order to increase positioning accuracy.
A robot control system is known from US 2004/0093119 A1 which corrects friction-related positioning errors of the robot in the case of drive regulation in the individual robot axes, the predetermined robot path not being modified however. The positioning accuracy of the robot is not therefore improved to a sufficient degree by this robot control system, this being particularly true in the case of highly dynamic operation of the robot.
Reference should also be made with regard to the prior art to DE 10 2004 056 861 A1; “Proceedings of the 2005 IEEE Conference on Control Algorithms”, Aug. 28-31, 2000, pp. 1170-1175; “Proceedings of IFAC Symposium on Robot Control”, Sep. 19-21, 1994, pp. 485-490; DE 698 29 559 T2; DE 10 2004 008 406 A1; “Proceedings of the 1992 IEEE Conference on Robotics and Automation”, May 1992, pp. 1429-1435; “IEEE Transactions on Control Systems Technology”, Vol. 12, No. 6, November 2004, pp. 904-919 and EP 1 173 801 B1. However, in this prior art, too, the positioning accuracy of the robot is unsatisfactory.
Accordingly, there is a need in the art for an improved control method for a multiaxial robot which compensates elasticities of the robot as well as possible, in order to improve the positioning accuracy of the robot.